The purpose of a permanent magnet is to produce flux in the working gap of a device. Obviously all permanent magnetic material will produce flux, but depending upon the working application, certain material types, grades and shapes will be more efficient than others. The following is a breakdown by product line applications that are most suitable for a material characteristics:

CAST ALNICO
The key attributes of Cast Alnico are:

• Mechanically strong
• Cast to a variety of shapes
• Very temperature stable
• Can change magnetic orientation
• High Br and Bhmax characteristics compared to ceramic materials.

SINTERED ALNICO
The key attributes of Sintered Alnico are:

• Mechanically strongest of the Alnicos
• Close tolerance pressing/typically minimum grinding

NOTE: Both cast and sintered Alnico have low Hc when compared to ceramic or rare earth materials.

ALNICO APPLICATIONS
General applications for both cast and sintered Alnico are:

• Electron tubes, radar, traveling wave tubes.
• Separators, holding magnets, coin acceptors, clutches and bearings.
• Magnetos, motors, generators, meters, instruments, controls, relays, watt-hour meters (bearings and dampeners).
• Communications, receivers, telephones, microphones, bell ringers, musical instruments (guitar pickups).
• Automotive sensors, loudspeakers, cow magnets, distributors.

FERRITE (CERAMIC) MAGNETS
Key attributes of ceramic magnets are:
Economical High Hc and Hci compared to Alnico

On the negative side, ceramics are good for simple shapes only, very fragile, require expensive tooling, and temperature sensitive (0.2%.)

FERRITE MAGNET APPLICATIONS
Generally ceramic magnets are used in:
DC permanent magnet motors used in the automobile industry for blowers, window lifts, windshield wipers, etc. (NOTE: Many of the motors come from outside sources not tied directly to the auto company itself). Separators to remove ferrous materials from liquid powder and bulk commodities.

Magnetic Resonate Imaging, MRI

Magnetos used on lawnmowers, garden tractors and outboard motors.

DC brushless motors with controllers for speed and direction.

SAMARIUM COBALT
While being quite expensive, samarium cobalt magnets are:
High Hc and Hci
High Bhmax
Very good temperature stability
Powerful for size

On the negative side, samarium cobalt is price sensitive due to cobalt supply and demand.

SAMARIUM COBALT APPLICATIONS
Samarium Cobalt is used in these general applications:
Traveling wave tubes
Computer rigid disc drives
D.C. Motors (where temperature stability is vital, such as, Military use-satellite systems, small military motors) sensors, growing automotive applications and linear actuators.

NEODYMIUM
Key reasons for using Neodymium are:
High energy for size
More economical than Samarium Cobalt
Good in ambient temperature situations
Very high Hc and Hci output

On the negative side of neodymium are relatively high price, corrosion that can result in loss of energy, and temperature coefficient of .13%/ degree centigrade.

NEODYMIUM APPLICATIONS
Some of the ever-growing list of uses are:
Computer rigid disc drives
Linear actuators
Hammerbank printers
Speakers
Microphone assemblies
Magnetic separators
DC Motors & Automotive starters
Servo Motors